您需要 Alamofire RequestRetrier 和 RequestAdapter 检查here https://github.com/Alamofire/Alamofire/blob/master/Documentation/AdvancedUsage.md
这是我的一些例子:
import UIKit
import Alamofire
class MyRequestAdapter: RequestAdapter, RequestRetrier {
private typealias RefreshCompletion = (_ succeeded: Bool, _ accessToken: String?) -> Void
private let lock = NSLock()
private var isRefreshing = false
private var requestsToRetry: [RequestRetryCompletion] = []
var accessToken:String? = nil
var refreshToken:String? = nil
static let shared = MyRequestAdapter()
private init(){
let sessionManager = Alamofire.SessionManager.default
sessionManager.adapter = self
sessionManager.retrier = self
}
func adapt(_ urlRequest: URLRequest) throws -> URLRequest {
var urlRequest = urlRequest
if let urlString = urlRequest.url?.absoluteString, urlString.hasPrefix(BASE_URL), !urlString.hasSuffix("/renew") {
if let token = accessToken {
urlRequest.setValue("Bearer \(token)", forHTTPHeaderField: "Authorization")
}
}
return urlRequest
}
// MARK: - RequestRetrier
func should(_ manager: SessionManager, retry request: Request, with error: Error, completion: @escaping RequestRetryCompletion) {
lock.lock() ; defer { lock.unlock() }
if let response = request.task?.response as? HTTPURLResponse, response.statusCode == 401 {
requestsToRetry.append(completion)
if !isRefreshing {
refreshTokens { [weak self] succeeded, accessToken in
guard let strongSelf = self else { return }
strongSelf.lock.lock() ; defer { strongSelf.lock.unlock() }
if let accessToken = accessToken {
strongSelf.accessToken = accessToken
}
strongSelf.requestsToRetry.forEach { $0(succeeded, 0.0) }
strongSelf.requestsToRetry.removeAll()
}
}
} else {
completion(false, 0.0)
}
}
// MARK: - Private - Refresh Tokens
private func refreshTokens(completion: @escaping RefreshCompletion) {
guard !isRefreshing else { return }
isRefreshing = true
let urlString = "\(BASE_URL)token/renew"
Alamofire.request(urlString, method: .get, parameters: nil, encoding: JSONEncoding.default, headers: ["Authorization":"Bearer \(refreshToken!)"]).responseJSON { [weak self] response in
guard let strongSelf = self else { return }
if
let json = response.result.value as? [String: Any],
let accessToken = json["accessToken"] as? String
{
completion(true, accessToken)
} else {
completion(false, nil)
}
strongSelf.isRefreshing = false
}
}
}
我的例子有点复杂,但是一般来说我们有两个重要的方法,第一个是adapt(_ urlRequest: URLRequest) throws -> URLRequest
在我们附加令牌的地方,这里我有自定义逻辑,其中一项服务不应将此令牌附加为标头。第二种方法是func should(_ manager: SessionManager, retry request: Request, with error: Error, completion: @escaping RequestRetryCompletion)
我在其中检查错误代码是什么(在我的示例中为 401)。然后我刷新我的令牌
private func refreshTokens(completion: @escaping RefreshCompletion)
就我而言,我有刷新令牌和访问令牌,当我使用刷新令牌调用服务时,我不应该在标头中附加旧的访问令牌。我认为这不是最佳实践,但它是由我不认识的人实施的。